#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
#include<string>
using namespace std;

int main()
{
	string s1("duoshaoshiconglaijiyiwanniantaijiuzhizhengzhaoxi");
	string s2;
	string s3(s1);
	cout << s1 << endl;
	cout << s2 << endl;
	cout << s3 << endl;
	string s4("duoshaoshiconglaijiyiwanniantaijiuzhizhengzhaoxi",0, 50);
	cout << s4 << endl;
	string s5("duoshaoshiconglaijiyiwanniantaijiuzhizhengzhaoxi", 19);
	cout << s5 << endl;
	return 0;
}